import React, { useEffect, useState } from 'react'
import logo from './logo.svg'
import './App.css'
import Child from './child'

function App() {
  const [msg, setMsg] = useState('Hello')
  // useEffect(() => {
  //   let timer = setInterval(() => {
  //     setMsg(msg + 'a')
  //   }, 1000)
  // }, [msg])
  return (
    <div className="App">
      <Child msg={msg} />
    </div>
  )
}

export default App
